The HVPF™ (High Volume Print-Forming) process of this invention is a new and unique manufacturing process with advantages in many applications and industries. This manufacturing process allows low cost production of small, complex structures or assemblies and co-fired ceramic circuits. A market exists for such structures with optimized designs not profitably manufacturable with current technologies that require the HVPF™ manufacturing process methods and devices. Included in these specialized devices presently described is the enabling support bed invention also referred to by the trademark “Ziggurat,” and associated substrate blocks also referred to by the trademark “Ziggys.” As will be described, the “Ziggurat” is a new species of a previously patented “Progressive Wedge” concept identified in U.S. Pat. No. 5,348,693, incorporated herein by reference.
HVPF™ manufacturing processes are 3-D (three-dimensional) print-forming methods that can produce structures or assemblies from virtually any material that can be printed, bonded or sintered, including ceramic, glass, metal or polymer, and combinations of these materials, at high speed and low cost. It is not a rapid prototyping process and has few of the limitations of rapid prototyping. Structures can be produced from multiple materials and specific engineered parts can be designed into complex functional geometries including mechanical structures with moving parts and “preassembled” components built in-situ. HVPF™ enables the manufacture of complex geometric structures without increasing manufacturing costs and it provides freedom from many typical manufacturing constraints, allowing form to more closely follow function.
HVPF™ processes capitalize on advances in a number of technologies, including printing, ceramic and metal injection molding, CAD/CAM, advanced materials, robotics, sensors and imaging. The printing portion of HVPF™ process is similar to “two-dimensional” printing including screen printing, flexo, gravure or offset lithography. HVPF™ differs in that subsequent prints are layered on top of each other, like the pages of a book, to print-form a three dimensional object, which is made entirely of the printed material. Different layers may contain different shapes, creating three-dimensional geometry when multiple layers are combined together, as shown in FIG. 1. Further detail on the background of high volume print-forming by the known progressive wedge technique can be found by reference to U.S. Pat. No. 5,348,693.
In its simplest form, the progressive wedge is physically a linear array of advancing unfinished structures, which are successively built from first to last, layer-by-layer, from the bottom-most layer upward. Only the last structure is complete as it receives the last layer. Every structure in the linear array receives the next layer on top of the previous layers at the same time as all the other structures, each structure getting the layer specifically required at its height at that time in the build sequence. With every cycle, the “oldest” structure comes off the end of the line finished, and one new structure is started at the beginning. The same printer image is printed every time, which consists of a linear array of cross section images of the structure. As noted before, there may be two or more materials used for each layer printed, and the structures only advance after all materials for that layer have been printed.
With structures that have many layers and relatively large dimensions, this progressive wedge and its associated printing machinery often would be, out of necessity, a proportionally long physical structure. The printer, with its repetitive print cycles, works with the progressive wedge as a printing platen, a means to reassemble a computer-generated structure that has been horizontally sliced into many thin, printable layers, into a real print-formed structure. As illustrated in FIG. 2, the cyclical action of the screen would print all the different and successive layers onto the forming structures below, all at the same time, over and over again. Between every print cycle, the structures move along the progressive wedge one step left to right.
The “progressive” aspect of the progressive wedge refers to the fact that the structures being built move or “progress” one place between every printing cycle as well as grow “progressively” in thickness with every printing cycle. Therefore, a structure starts out at one end of the progressive wedge by its first layer being printed onto a flat formation site. The partial structure then receives the second layer on top of the first and so on until it finishes at the other end with the last layer being printed on top of all the previous layers. This would be analogous to a waiter collecting plates, each of a different shape than the last, and stacking them on top of each other until there is a tall stack. The individual plates represent the print cycles; the stack represents the full structure.
The “wedge” aspect of the progressive wedge is specifically regarding the growing height of the individual structures as they move relative to the image being printed. The collective shape of the structures in progress forms a wedge in side view, with the thin end of the wedge at the beginning of the printing line and the thick end at the “finished structures” end. Being that the top surface of the wedge must remain level and parallel with the printing plane, the bottom surface of the structures must be progressively lowered one layer thickness at a time, as they advance. Using the plate analogy again, imagine the stack of plates in an automatic plate dispenser that keeps the top plate level with the serving table by adjusting the height of the bottom plate in the stack.